In a case where an electrode pattern is formed on an insulating substrate, for example, on a print substrate, the electrode pattern is generally formed by etching after pasting a copper foil to a base via an adhesive layer. In addition, on a ceramics substrate, the electrode pattern is generally formed by electrolytic plating after printing a conductive pattern that becomes a ground of the electrode by a conductive paste.
Furthermore, a method of forming an electrode pattern by forming a thin film of metal having a high melting point, such as Ni, Ti, Co, or Cr, by a sputtering method, on the substrate, by further forming a thin copper film by a sputtering method, and then, on seed metal using the metal thin film as seed metal, by forming a thick film of Cu by electrolytic plating, on the substrate on which an alumite layer is formed as an insulation layer on an aluminum base, is disclosed, for example, in PTL 1 and PTL 2.